1. Field of the Invention
The present invention relates generally to construction machines of a crawler type, and more particularly, to construction machines in which spatial interval between respective left and right crawler track devices can be varied.
2. Description of the Related Art
Some compact hydraulic excavators are equipped with a vehicle width changer. Such a vehicle width changer enables width of the vehicle or a spatial interval between left and right crawler track devices of the vehicle to be extended for improved traveling stability and enhanced excavating stability of the vehicle body. The vehicle width changer also enables the vehicle width to be narrowed down for traveling through confined spaces such as an alley, or for being loaded and carried on mini-trucks.
For example, operating means for a vehicle width changer is already placed in practical use. In such operating means, a blade-lifting lever disposed to the right of an operator cab also serves as a vehicle width changing control lever, with switching between the two lever functions being conducted by switching the solenoid valve using an operator switch. Another known example includes, as described in JP-2000-198471-A, a control lever (hereinafter, referred to as a vehicle width changing control lever) on a front side of a seat base under an operator's seat.